The temporary neighborhood statistics grid was used as the input surface and the contour interval was set to 1 meter. Studies have shown that the anisotropic effects of skin have. Our approach is based on the creation and characterisation of. How to read topography maps and delineate watershed boundaries. What similar or related data should the user be aware of. Mark four points two on the endpoints, and two between and draw the contours. Online army study guide land navigation map reading. The principal characteristics of contour lines which help in plotting or reading a contour map are as follows. The topographical maps, which have been referred to in chapter 1. The topo to raster tool is an interpolation method specifically designed for the creation of hydrologically correct digital elevation models dems. Features of contour lines are helpful in plotting and interpretation of several features in the map. Characteristics of contour lines a contour line is a line of equal elevation. You have an image file behind objects or text that have transparency.
Contour line do not cross characteristics of contours topographic. Characteristics of contour lines, contouring, assignment help. Contour lines contour lines, or isohypses, connect points of equal elevation. Fstopo pdf tags fstopo, topographic, quadrangle, cartographic, imagerybasemapsearthcover summary the fstopo pdf maps are geoenabled pdf files for the entire set of forest service primary base series topographic quadrangle maps created from the fstopo database. What are the difference between tender and contract documents.
What links here related changes upload file special pages permanent link. It creates a 3d map or a contour chart from the scattered points, numerical arrays or other data sets. A contour line always rejoins or closes upon itself to form a loop, although this may or may not occur within the map area. It has contour lines to show the shape and elevation of the land. Closed contours correspond to region boundaries, and the pixels in the region may be found by a filling algorithm. It would be fairly flat not a lot of change in elevation. Colors and symbols are used to represent other features on the land, such as water, vegetation, roads. You can set properties that apply formatting, determine how the form field information relates to other form fields, impose limitations on what the user can enter in the form field, trigger custom scripts, and so on. Following are the characteristics of contour lines in surveying for reading contour maps. Depression contours should not cross singleline streams more than once. Imagine a land surface inundated by the sea to a depth of 100 feet 30. All contour lines eventually connect with themselves. If it closes beyond the limits of the map it will run to the map edge.
Contour lines mark points of equal elevation on a map and are critical to understand the elevation profile of your terrain. Pdf a design of contour generation for topographic maps. The closer together the lines are, the steeper the slope. Contour lines are a key features of topographic maps as they make the comprehension of terrain more easy. Contour line, a line on a map representing an imaginary line on the land surface, all points of which are at the same elevation above a datum plane, usually mean sea level. Aug 22, 2015 drawing the contour lines contour lines are drawn as fine and smooth free hand curved lines. Use contour lines to determine elevations of mountains and. Download pdf version download flashcards online flashcards. It will export polygons, but youll have better luck achieving the effect in your favorite graphics editing software. Generating contour lines using different elevation data file. The top of this drawing is a contour map showing the hills that are illustrated at the bottom. On contour lines the level of lines is also written. So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists on the ground figure 818 shows an overhanging cliff. The contour lines in an area are drawn keeping difference in elevation of between two consecutive lines constant.
There are several types of contour line drawings, the most used and famous are the following ones. In cartography, the contour interval is the elevation difference between adjacent contour lines. Maps are flat unlike some of the ground which they represent so we use contour lines on a map to show how high the ground is. Contour lines were generated were generated using the contour operation. In economics, contour lines can be used to describe features which vary. They are sometimes called level lines because they show points that are at the same level. Depression contours should not cross single line streams more than once. Every contour closes on itself either within or beyond the limits of the map. A detailed guide to contour lines, formations, drawings, hills and depressions. The word relief as related to topographic maps means what. All points along the same contour line are at the same elevation. Divide 300 feet by 3 to get one contour every 100 feet. Edges must be linked into a representation for a region boundary.
The contours maps have the following characteristics. To properly analyze and evaluate this information, all topographic lines, elevation numbers, and spot elevations must be legible. Dark brown lines are called index contour lines and their elevation is written in dark brown somewhere along the contour line. A contour line is an imaginary outline of the terrain obtained by joining its points of equal elevation. Open contours also occur when line fragments are linked togetherfor example, when line fragments are linked along a stroke in a drawing or sample of handwriting. A contour line of a function of two variables is a curve along which the function has a constant. Summarize 3 rules or characteristics of contour lines that you have learned from this activity. Fstopo pdf maps are created using fstopo map symbology and specifications. The interval between contour lines varies and this interval is noted underneath the scale on 7. The contours eo denote ascending contours, while the hachured contours ad denote descending. Evenly spaced contour lines indicate a uniform slope. Gilchrist1 abstract the mechanical properties of skin are important for a number of applications including surgery, dermatology, impact biomechanics and forensic science.
But before we are discussing about drawing contour lines in qgis, lets start talking a little bit about the concept of contour line, what contour line definition is, contour lines characteristics and and how the method in drawing contour line. Contour lines describe the shape of an object, and include interior detail. The elicited contour semantics comprises four key concepts contour regions, contour lines, contour values, and. Suppose a map includes contour lines of 100m, 98m,96 m and so on. They never cross, split or intersect at a cliff they might merge. Contour lines mark points of equal elevation on a map and are critical to. On this map, the vertical distance between each contour line. A drawing pen gives a better line than a writing pen and french curves should be used as much as possible. The line is generalized using a tension parameter in analogy with the tensionextension of materials with linear elasticity. Topographic maps and countours academic resource center.
White or dark lines appear in areas where process colors and spot colors interact during flattening. The particular contour located at a particular station depends on 1 the ground elevations and 2 the specified contour interval. These lines are typically used for basemaps and general topographic representation. Contour lines are lines drawn on a map connecting points of equal elevation. Based on spatial relation theory and geometric characteristics of contours, qiao et al. These defects in strip are measured with optoelectronic semiconductor sensors.
Lines close at the top of a slope and wider apart at the bottom indicate a concave slope. Download as ppt, pdf, txt or read online from scribd. Centrifugal pump exercise b objective to create head, power and efficiency characteristic curves for a centrifugal pump. In cartography, contour lines are imaginary lines of a terrain that joins point of equal elevation above a given level, such as mean sea level or.
How to read and understand topographical maps for trails and hiking while backpacking or in a survival situation. Contour lines characteristics of contour lines are. So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists. All aspects of 2d or 3d maps can be customized to produce exactly the presentation you want. Its not necessary in this case since youre plotting the line after the contours it should have a higher zorder than the contour lines by default. Pu 09,10,14 contour interval ci it is the vertical distance between any two consecutive contours. It is based on the anudem program developed by michael hutchinson 1988, 1989, 1996, 2000, 2011. If you have an area of low relief what would the land look like. The gradient symbol in maxwells equations includes the gra dient in all three dimensions, not just two as in this map. Lecture on basics characteristics of contour lines by raaj ramsankaran bits.
Readingunderstanding topographic maps school of forest. Contour lines allow you to infer general terrain characteristics from. Imaginary line joining points of equal elevation above or below a datum contour lines have a specific contour interval interval is the vertical distance between contours ci is a function of scale and units. On a map the contour lines will be spaced closer together with a decline in height above sealevel. A contour is a line through all contiguous points of equal value. The tension parameter is locally adapted to a selected set of line characteristics. Contour elevation numbers indicate the direction of elevation by always reading pointing uphill. Contour lines must close, not necessarily in the limits of the plan. Topographic survey civl 1101 surveying introduction to topographic modeling 19. Brown used to depict contour lines as well as some landform features. Once youre familiar with these features and what theyre called, you can begin to study your topo map and try to picture in your minds eye the shape of the terrain. Survey lines definitions a survey line is a line produced on a cast by a surveyor or scribe marking the greatest prominence of contour in relation to the planned path of placement of a restoration. You also know that maps are classified on the basis of scale and functions. Also, since youre drawing a straight line with only two points.
Contour line connects points of equal elevation, the contour interval represents the vertical distance between contour lines, and the base contour is the contour from which contouring starts. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The gis project maintains links to the individual data files the data is not embedded in the map document itself gis formats, like shapefile shp, have many files that are linked together and must stay together in order to function descriptions of the files you create and use arccatalog. Pdf compressive strength of concrete cube test pdf. The contour line represented by the shoreline separates.
Contour lines represent the shape and elevation of the land, such as ridges, valleys, and hills. You would draw lines that would follow along the form. Irregularly shaped contour lines, particularly zigzag contour lines, denote rugged, uneven terrain. B touches six heavy brown lines for a gradient of 600 2,000 0. Terrain features of elevation and relief can be depicted by contour lines. All points on a contour line have the same elevation. Contour lines drawings are made up of only lines, no shading for interest, modify how thick or thin your lines are. Contour lines types, characteristics and uses in surveying. Pdf contours maps such as topographic maps compress the. Theory one way of illustrating pump characteristics is to construct contour lines of. When using spot elevations, there should be a sufficient number of points to be able to visualize the site topography. Each drawing below violates a rule of contour lines. The estimated height of both the contour lines of that area is same, but the contour lines are drawn differently.
Contour line is the most common usage in cartography, but isobath for underwater depths on bathymetric maps and isohypse for elevations are also used. The method used to locate the contours is the one described earlier for tracing a contour system. A uniform slope is indicated by evenly spaced contours. Chapter 5 topographical maps you know that the map is an important geographic tool. Think of an ant crawling across the object or a topographic map.
Arc and node characteristics play the elemental role for the. Surveying contour lines and its types, characteristics and uses in surveying contour lines and its types, characteristics and uses in surveying in cartography, contour lines are an imaginary line of a terrain that joins the point of equal elevation above a given level, such as mean sea level or benchmark. Characteristics of contour contours of different elevations cannot cross each other caves and overhanging cliffs are the exceptions. A line marked 6500, for example, means that point on the map is 6,500 feet above sea level. Contour crenulations should conform to reentrants fig. Concave slope a slope which becomes progressively steeper uphill.
The contour interval for a quad is the larger of the. So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists on the. The closer contour lines are together on a map, the steeper the slope of the landform. On a map the contour lines will be spaced closer with an increase in height above sealevel. These contour lines are an important way of showing the rise and fall of the land on a map. The purpose is the generalization of contour lines of medium scale maps 1. Topographic survey topographic survey the most common method of representing the topography of an area is to use contour lines contours a contour lineis an imaginary level line that. This video provides an introduction to understanding topographic maps. Contour line connects points of equal elevation, the contour interval. But they are no longer drawn by cartographers, they are mostly automatically derived from.
Representing heights on maps professor keith clarke contours on maps. On each of the dotted crosssection lines, contours are located. By following a contour line on the ground, you would travel neither uphill nor downhill, eventually ending up back at your starting point. For example, tightly clumped contour lines might depict a cliff while widely spaced contour lines. Contour lines in art show only the outermost silhouette and the important inner shapes of any. Regression methodology for bivariate heteroscedastic data pdf. You can just get rid of the third array argument to plt. A contour line is a imaginary line which connects points of equal elevation. Examples of curves include line segments and cubic splines. Imaginary line joining points of equal elevation above or below a datum contour lines have a specific contour interval interval is the vertical distance between contours ci is a. Contour lines are used as a familiar media for representing the elevations of a land surface above sea level. Index contour lines are separated by lighter brown contour lines called intermediate contour lines.
Thicker for major lines, thinner for highlights, or soft implied edges. When you export to adobe pdf from indesign, white or dark lines are visible in the pdf file. The variation of vertical distance between any two contour lines is assumed to be uniform. How terrain features are depicted with contour lines. A contour may be represented as an ordered list of edges or by a curve. Generating contour lines using different elevation data. Contour line drawing is a great place for an aspiring artist to begin. When contour lines are found to be spaced far apart, what type of landform is usually found. Shaded relief is sometimes used in conjunction with contour lines to emphasize these features. The line ab is a traverse along which 100foot stations are shown. A contour line is drawn to show places of equal heights.
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